text: /**********************************************************************
   * File:        word_size_model.cpp
   * Description: Implementation of the Word Size Model Class
   * Author:    Ahmad Abdulkader
   * Created:   2008
   *
   * (C) Copyright 2008, Google Inc.
   ** Licensed under the Apache License, Version 2.0 (the "License");
   ** you may not use this file except in compliance with the License.
   ** You may obtain a copy of the License at
   ** http://www.apache.org/licenses/LICENSE-2.0
   ** Unless required by applicable law or agreed to in writing, software
   ** distributed under the License is distributed on an "AS IS" BASIS,
   ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   ** See the License for the specific language governing permissions and
   ** limitations under the License.
   *
   **********************************************************************/
  
  #include <math.h>
  #include <string>
  #include <vector>
  #include "word_size_model.h"
  #include "cube_utils.h"
  
  namespace tesseract {
  
  WordSizeModel::WordSizeModel(CharSet * char_set, bool contextual) {
    char_set_ = char_set;
    contextual_ = contextual;
  }
  
  WordSizeModel::~WordSizeModel() {
    for (int fnt = 0; fnt < font_pair_size_models_.size(); fnt++) {
      FontPairSizeInfo fnt_info = font_pair_size_models_[fnt];
      delete []fnt_info.pair_size_info[0];
      delete []fnt_info.pair_size_info;
    }
  }
  
  WordSizeModel *WordSizeModel::Create(const string &data_file_path,
                                       const string &lang,
                                       CharSet *char_set,
                                       bool contextual) {
    WordSizeModel *obj = new WordSizeModel(char_set, contextual);
  
    if (!obj->Init(data_file_path, lang)) {
      delete obj;
      return NULL;
    }
    return obj;
  }
  
  bool WordSizeModel::Init(const string &data_file_path, const string &lang) {
    string stats_file_name;
    stats_file_name = data_file_path + lang;
    stats_file_name += ".cube.size";
  
    // read file to memory
    string str_data;
  
    if (!CubeUtils::ReadFileToString(stats_file_name, &str_data)) {
      return false;
    }
  
    // split to words
    vector<string> tokens;
    CubeUtils::SplitStringUsing(str_data, "\t\r\n", &tokens);
    if (tokens.size() < 1) {
      fprintf(stderr, "Cube ERROR (WordSizeModel::Init): invalid "
              "file contents: %s\n", stats_file_name.c_str());
      return false;
    }
  
    font_pair_size_models_.clear();
  
    // token count per line depends on whether the language is contextual or not
    int token_cnt = contextual_ ?
        (kExpectedTokenCount + 4) : kExpectedTokenCount;
    // the count of size classes depends on whether the language is contextual
    // or not. For non contextual languages (Ex: Eng), it is equal to the class
    // count. For contextual languages (Ex: Ara), it is equal to the class count
    // multiplied by the position count (4: start, middle, final, isolated)
    int size_class_cnt = contextual_ ?
        (char_set_->ClassCount() * 4) : char_set_->ClassCount();
    string fnt_name = "";
  
    for (int tok = 0; tok < tokens.size(); tok += token_cnt) {
      // a new font, write the old font data and re-init
      if (tok == 0 || fnt_name != tokens[tok]) {
        FontPairSizeInfo fnt_info;
  
        fnt_info.pair_size_info = new PairSizeInfo *[size_class_cnt];
  
        fnt_info.pair_size_info[0] =
            new PairSizeInfo[size_class_cnt * size_class_cnt];
  
        memset(fnt_info.pair_size_info[0], 0, size_class_cnt * size_class_cnt *
               sizeof(PairSizeInfo));
  
        for (int cls = 1; cls < size_class_cnt; cls++) {
          fnt_info.pair_size_info[cls] =
              fnt_info.pair_size_info[cls - 1] + size_class_cnt;
        }
  
        // strip out path and extension
        string stripped_font_name = tokens[tok].substr(0, tokens[tok].find('.'));
        string::size_type strt_pos = stripped_font_name.find_last_of("/\\");
        if (strt_pos != string::npos) {
          fnt_info.font_name = stripped_font_name.substr(strt_pos);
        } else {
          fnt_info.font_name = stripped_font_name;
        }
        font_pair_size_models_.push_back(fnt_info);
      }
  
      // parse the data
      int cls_0;
      int cls_1;
      double delta_top;
      double wid_0;
      double hgt_0;
      double wid_1;
      double hgt_1;
      int size_code_0;
      int size_code_1;
  
      // read and parse the tokens
      if (contextual_) {
        int start_0;
        int end_0;
        int start_1;
        int end_1;
        // The expected format for a character size bigram is as follows:
        // ClassId0<delim>Start-flag0<delim>End-flag0<delim>String0(ignored)
        // Width0<delim>Height0<delim>
        // ClassId1<delim>Start-flag1<delim>End-flag1<delim>String1(ignored)
        // HeightDelta<delim>Width1<delim>Height0<delim>
        // In case of non-contextual languages, the Start and End flags are
        // omitted
        if (sscanf(tokens[tok + 1].c_str(), "%d", &cls_0) != 1 ||
            sscanf(tokens[tok + 2].c_str(), "%d", &start_0) != 1 ||
            sscanf(tokens[tok + 3].c_str(), "%d", &end_0) != 1 ||
            sscanf(tokens[tok + 5].c_str(), "%lf", &wid_0) != 1 ||
            sscanf(tokens[tok + 6].c_str(), "%lf", &hgt_0) != 1 ||
            sscanf(tokens[tok + 7].c_str(), "%d", &cls_1) != 1 ||
            sscanf(tokens[tok + 8].c_str(), "%d", &start_1) != 1 ||
            sscanf(tokens[tok + 9].c_str(), "%d", &end_1) != 1 ||
            sscanf(tokens[tok + 11].c_str(), "%lf", &delta_top) != 1 ||
            sscanf(tokens[tok + 12].c_str(), "%lf", &wid_1) != 1 ||
            sscanf(tokens[tok + 13].c_str(), "%lf", &hgt_1) != 1 ||
            (start_0 != 0 && start_0 != 1) || (end_0 != 0 && end_0 != 1) ||
            (start_1 != 0 && start_1 != 1) || (end_1 != 0 && end_1 != 1)) {
          fprintf(stderr, "Cube ERROR (WordSizeModel::Init): bad format at "
                  "line %d\n", 1 + (tok / token_cnt));
          return false;
        }
        size_code_0 = SizeCode(cls_0, start_0, end_0);
        size_code_1 = SizeCode(cls_1, start_1, end_1);
      } else {
        if (sscanf(tokens[tok + 1].c_str(), "%d", &cls_0) != 1 ||
            sscanf(tokens[tok + 3].c_str(), "%lf", &wid_0) != 1 ||
            sscanf(tokens[tok + 4].c_str(), "%lf", &hgt_0) != 1 ||
            sscanf(tokens[tok + 5].c_str(), "%d", &cls_1) != 1 ||
            sscanf(tokens[tok + 7].c_str(), "%lf", &delta_top) != 1 ||
            sscanf(tokens[tok + 8].c_str(), "%lf", &wid_1) != 1 ||
            sscanf(tokens[tok + 9].c_str(), "%lf", &hgt_1) != 1) {
          fprintf(stderr, "Cube ERROR (WordSizeModel::Init): bad format at "
                  "line %d\n", 1 + (tok / token_cnt));
          return false;
        }
        size_code_0 = cls_0;
        size_code_1 = cls_1;
      }
  
      // copy the data to the size tables
      FontPairSizeInfo fnt_info = font_pair_size_models_.back();
      fnt_info.pair_size_info[size_code_0][size_code_1].delta_top =
          static_cast<int>(delta_top * kShapeModelScale);
      fnt_info.pair_size_info[size_code_0][size_code_1].wid_0 =
          static_cast<int>(wid_0 * kShapeModelScale);
      fnt_info.pair_size_info[size_code_0][size_code_1].hgt_0 =
          static_cast<int>(hgt_0 * kShapeModelScale);
      fnt_info.pair_size_info[size_code_0][size_code_1].wid_1 =
          static_cast<int>(wid_1 * kShapeModelScale);
      fnt_info.pair_size_info[size_code_0][size_code_1].hgt_1 =
          static_cast<int>(hgt_1 * kShapeModelScale);
  
      fnt_name = tokens[tok];
    }
  
    return true;
  }
  
  int WordSizeModel::Cost(CharSamp **samp_array, int samp_cnt) const {
    if (samp_cnt < 2) {
      return 0;
    }
    double best_dist = static_cast<double>(WORST_COST);
    int best_fnt = -1;
    for (int fnt = 0; fnt < font_pair_size_models_.size(); fnt++) {
      const FontPairSizeInfo *fnt_info = &font_pair_size_models_[fnt];
      double mean_dist = 0;
      int pair_cnt = 0;
  
      for (int smp_0 = 0; smp_0 < samp_cnt; smp_0++) {
        int cls_0 = char_set_->ClassID(samp_array[smp_0]->StrLabel());
        if (cls_0 < 1) {
          continue;
        }
        // compute size code for samp 0 based on class id and position
        int size_code_0;
        if (contextual_) {
          size_code_0 = SizeCode(cls_0,
                                 samp_array[smp_0]->FirstChar() == 0 ? 0 : 1,
                                 samp_array[smp_0]->LastChar() == 0 ? 0 : 1);
        } else {
          size_code_0 = cls_0;
        }
  
        int char0_height = samp_array[smp_0]->Height();
        int char0_width = samp_array[smp_0]->Width();
        int char0_top = samp_array[smp_0]->Top();
  
        for (int smp_1 = smp_0 + 1; smp_1 < samp_cnt; smp_1++) {
          int cls_1 = char_set_->ClassID(samp_array[smp_1]->StrLabel());
          if (cls_1 < 1) {
            continue;
          }
          // compute size code for samp 0 based on class id and position
          int size_code_1;
          if (contextual_) {
            size_code_1 = SizeCode(cls_1,
                                   samp_array[smp_1]->FirstChar() == 0 ? 0 : 1,
                                   samp_array[smp_1]->LastChar() == 0 ? 0 : 1);
          } else {
            size_code_1 = cls_1;
          }
          double dist = PairCost(
              char0_width, char0_height, char0_top, samp_array[smp_1]->Width(),
              samp_array[smp_1]->Height(), samp_array[smp_1]->Top(),
              fnt_info->pair_size_info[size_code_0][size_code_1]);
          if (dist > 0) {
            mean_dist += dist;
            pair_cnt++;
          }
        }  // smp_1
      }  // smp_0
      if (pair_cnt == 0) {
        continue;
      }
      mean_dist /= pair_cnt;
      if (best_fnt == -1 || mean_dist < best_dist) {
        best_dist = mean_dist;
        best_fnt = fnt;
      }
    }
    if (best_fnt == -1) {
      return static_cast<int>(WORST_COST);
    } else {
      return static_cast<int>(best_dist);
    }
  }
  
  double WordSizeModel::PairCost(int width_0, int height_0, int top_0,
                                 int width_1, int height_1, int top_1,
                                 const PairSizeInfo& pair_info) {
    double scale_factor = static_cast<double>(pair_info.hgt_0) /
        static_cast<double>(height_0);
    double dist = 0.0;
    if (scale_factor > 0) {
      double norm_width_0 = width_0 * scale_factor;
      double norm_width_1 = width_1 * scale_factor;
      double norm_height_1 = height_1 * scale_factor;
      double norm_delta_top = (top_1 - top_0) * scale_factor;
  
      // accumulate the distance between the model character and the
      // predicted one on all dimensions of the pair
      dist += fabs(pair_info.wid_0 - norm_width_0);
      dist += fabs(pair_info.wid_1 - norm_width_1);
      dist += fabs(pair_info.hgt_1 - norm_height_1);
      dist += fabs(pair_info.delta_top - norm_delta_top);
    }
    return dist;
  }
  }  // namespace tesseract
  